Several different types of packaging systems have been evolved for display packaging of articles including blister packaging, skin packaging, and stretch and shrink film packaging. Blister and skin packaging have been particularly useful in providing relatively rigid substrates for supporting and protecting the article being packaged during storage, shipment and display.
Although blister packaging offers the advantage of using less film area, the blister must be preformed and generally of heavier gauge film so that it tends to provide less resilient deformation. Moreover, the blister generally tends to be of greater height dimension than the article being enclosed because of the difficulties in maintaining close tolerances, thus frequently permitting the article to more about within the blister. Since the area for bonding the blister to the substrate comprises a relatively narrow flange, there is sometimes a problem with respect to effecting the necessary high degree of adhesion to resist the stresses occurring during impact and the shear stresses when the articles and cartons are displayed vertically.
On the other hand, skin packaging affords significant advantages in that the film may be of considerably thinner gauge and may exhibit considerably greater tendency for resilient deformation. Moreover, the film is drawn about the article into a tight fitting sheath so that the article is restrained from movement therewithin, and the film is bonded to the substrate over substantially the entire face of the card except that portion overlain by the article. However, skin packaging can present significant problems when dealing with articles which are of varying profile height, of lesser cross section adjacent their lower ends, crushable, hollow or apertured, fibrous or bristled, etc. With articles of these types, since the hot thermoplastic film is drawn by the vacuum into a tight fitting sheath about the article, it tends to crush fibrous or other soft materials and to deform into recesses or cavities about the surface of the article and will be drawn under the area of maximum cross section of articles of irregular shape and cylinders. This can result in an aesthetically undesirable appearance or excessive reduction in the thickness of the sheath or actual damage to the product.
It is an object of the present invention to provide a novel form of skin packaging in which the sheath tightly fits about the periphery of the article but does not extend into recesses or inwardly of the area of maximum cross section.
It is also an object to provide apparatus for making such a skin package which is readily adaptable to articles of fibrous or soft material, or which are round or cylindrical, or which are irregular in profile, since the sheath will conform closely to the area of maximum cross section but will not deform inwardly thereof.
Another object is to provide such apparatus, which is simple and effective in operation and which is rugged in construction.